Lathe-dog



(No Model.)

H.. E. HOLMES. LATHE DOG- No. 418,464, PatentedvDec 31', 1889.

UNITED STATES PATENT 0FFICE HERBERT E. HOLMES, OF l/VEST SPRINGFIELD,MASSACHUSETTS.

LATHE-DOG.

SPECIFICATION forming part of Letters Patent No. 418,464, dated December31, 1889.

Application filed October 31, 1889- Serial No. 328,833. (No model.)

To all whom, it may concern:

Be it known that I, HERBERT E. HoLMEs, a citizen of the United States,residing at West Springfield, in the county of I-Iampden and State ofMassachusetts, have invented new and useful Improvements in Lathe-Dogs,of which the following is a specification.

This invention relates to lathe-dogs, the obj ect being to provide animproved implement of this class which is adapted by simple means tobring the piece to which it maybe attached, whereby it is held forturning in a lathe or for other similar operation to a central positionin the eye of the lathe-dog, and whereby one dog is adapted in suchmanner to hold the ends of pieces to be operated upon which havedifferent diameters, and also to efficiently hold metallic pieces havingscrew-threaded ends to which the lathe-dog is attached without marringor injuring the screw-threaded parts of said pieces; and the inventionconsists in the peculiar construction of the lathe-dog and itsattachments, all as hereinafter fully described, and pointed out in theclaims.

In the drawings forming part of this specification, Figure 1 is a rearelevation,and Fig. 2 a side elevation, partly in section, of a lathedogand attachments embodying my improvements, said two figures illustratingsaid attachments internally screw-threaded. Fig. 3 is a sectional viewof that portion of a lathedog surrounding the eye thereof, and showingin section said lathe-dog attachment not screw-threaded, and the bindingor set screw of the lathe-dog passing through the side of saidattachment. Fig. 4 is a perspective view of the lathe-dog and of ascrew-threaded attachment therefor. Fig. 5 is a perspective view of oneof said lathe-dog attachments whose interior is not screw-threaded. Fig.6 illustrates in end view several of said lathedog attachments havingdifferent internal diameters.

In the drawings, A indicates the lathe-dog, provided with the usualopening or eye 2, in which the end of a piece of metal or other thing isinserted when the lathe-dog is attached thereto to form a connectiontherewith and between it and a lathe, whereby rotary motion is impartedto said piece or thing by said lathe, said piece being secured in thelathe-dog by the set-screw 3,the arm 4 of said dog being adapted forengagement with the slotted face-plate on the spindle of the lathe orother object thereon, whereby the lathe-dog and the thing held by it arecaused to rotate coincident with the lathespindle in a manner Well knownto machinists and others conversant with the use of such tools.

Lathe-dogs as heretofore made, of the description illustrated in thedrawings, consisting only of the lathe-dog and its set-screw 3, havecontained a circular eye to receive the end of the work not adapted tovarying diameters of the pieces of work to which the dog may be applied,and hence when the lathedog so made is attached to the end of acylindrical piece of metal, or one of other exterior form considerablysmaller in cross-section than the eye of the lathe-dog, the latter iswith difficulty secured to said piece with the requisite firmness, fromthe fact that only a small portion of the interior wall of the eye ofthe lathe-dog is held in contact with the side of the piece securedtherein,"and under these conditions the set-screw 3 must necessarily beso forced against said piece as to injuriously indent or mark it; and,furthermore, when it is desired to'attach a lathe-dog of the abovedescription to a piece of metal having a screw-threaded end the dogcannot be attached close to the end thereof or at the end without firstputting a nut or similar piece on said screw-threaded part, lest thescrew-thread on the piece should be defaced or ruined by the action ofthe set-screw of the dog, said nut-bearing end of the piece to beoperated upon being inserted in the eye of the dog and there secured byforcing the setscrew against the side of the nut.

To obviate the above-named inconveniences and to provide simpleandinexpensive means therefor, I construct the lathe-dog A with the eye2 thereof having on its interior wall a 95 projection or rib c, as shownin Fig. 4, and for the lathe-dog eye thus made I construct severalattachments or bushings 5, adapted to be inserted in the eye of thelathe-dog in the positions shown in Figs. 1, 2, and 3 of the draw- :00

named figure, passes through an aperture e i in the side of the bushing5, when the cyllndrical chamber therein has a plane face or is notscrew-threaded, thereby permitting the screw to bear directly againstthe side of a piece of metal placed through said chamber and bind itrigidly therein when the screw is turned against it to attach the dogthereto. I do not wish it to be understood by the above description thatI would not under said circumstances make the eye of the lathe-dog withthe rib ctherein, because said rib by its engagement with the bushing,as below described, aids in firmly holding the work from rotating withinthe lathe-dog while being turned and as firmly as would be the resultwere the lathe-dog eye cylindrical and the piece of work to which it maybe attached fitted closely in the eye and was there secured by saidset-screw.

The bushings 5 for a lathe-dog having an eye of a given diameter are ofa like ex- .teriorjdiameter to fit said eye, but have varying diametersof chambers b, as shown in Fig. 6, and said bushings have a longitudinalgroove 0 in the side thereof, which,

when the bushing is placed in the eye of the 1 lathe -Vdog, receivessaid projection c on the wallet said eye. The said bushings 5, as before mentioned, may be made with either a planechamber, as shown inFigs. 3 and '5, or

with said chamber screw-threaded, as shown in Figs. 2 and at, saidbushings, whether having a screw-threaded or plane chamber, be-

ing adapted to be used on different descri'ptions of work in which thelathe-dog is emplo'yed, as above described.

In using the screw-threaded bushing in connection with a metal piecehaving a screw threaded end, to which it is desirable to attach thelathe-dog, the threaded bushing is placed in the eye of the dog in theposition shown-in Fig. 2, the screw 3 being turned thereagainst to holdit from being accidentally drawn outof the eye.

In practice a number of bushings of suitable metallic construction areprovided, with each lathe-dog comprising. several having plane chambersZ) therein of diiferent diam-. eters and several having screw-threadedchambers therein, adapted to the screwthreads of the work with which thelathedogs are to be used; or with each lathe-dog are supplied a numberof bushings having plane chambers therethrough, and the purchaser ofsaid dogs and bushings may tap them out to suit his convenience, suchbushings as shall be internally screw-threaded to be used, as aforesaid,without any side aperture e, and those which are to be used with theplane chamber '1) having said aperture 6 made therethrou'gh.

What I claim as my invention is I In combination, a lathe-dog having acylindrical eye, a projection on th'jewall of said eye, a set-screwpenetrating the same, and a cylindrical bushing having a groove in itssurface in which said projection engages, and a side aperture in whichsaid sc'rew enters, substantially as set forth.

2. In combination, a lathe-dog having a cylindrical eye, a projection onthe wall of said eye, a set-screw projecting into the same,

and several cylindrical bushings of varying internal diameters, eachh'avingfa groove its surface in which said projection engages, and aside aperture in which said screw enters, substantiallyas set forth.

3. In combination, a lathe-dog having a cylindrical eye, a projection onthe wall of said eye, a set-screw projecting into the same, and acylindrical bushing having its chamber screw-threaded, and a groove inits surface in which said projection engages, substantially as setforth.

HERBERT E. HOLMES.

Witnesses:

H. A. CHAPIN,

M. CHAMBERLAIN.

